Selector switches



March 13, 1962 Filed May 14, 1959 R. E. HARTSOCK ET AL SELECTOR SWITCHES 5 Sheets-Sheet l e7/mw' 19221273055 BY 7g/wwf 7307 JJM/I ATTORNEY March 13, 1962 R. E. HARTSOCK ET AL SELECTOR SWITCHES Filed May 14, l959 5 Sheets-Sheet 2 @naif fil/957K ATTORNEY March 13, 1962 R E, HARTSOCK ETAL 3,025,361

SELECTOR SWITCHES Filed May 14, 1959 f #B4/? #Hammam 5 Sheets-Sheet 3 iq/@xsf gwswar 3% WM,

ATTORNEY lltited States Patent @hice 3,025,351 Patented Mar. 13, 1962 said James G. Hartsock assignor to said Robert E. Hartsock Filed May 14 1959, Ser. No. 813,175 6 Claims. (Cl. 200-11) This invention relates to electric switching devices, and more particularly to such devices embodying selective switching means for a plurality of circuits,

With conventional rotary switch constructions, it is impractical to build a switch having more than about a huna dred positions.

The ever increasing complexity of electrical apparatus has developed a need for selector switches capable of handling a far greater number of circuits, and'renders more and more desirable the provision of something havmg a much larger range than the simple rotary switch.

This might be accomplished by arranging the series of fixed contacts in a helical path, as by mounting them on the surface of a helicoidal supporting structure of insulating material, and driving the movable contact so that it follows such helical path. Theoretically, this would provide an answer to the problem, as in such an arrangement it is possible to utilize a very large number of fixed contacts. In practice, however, it is apparent that such a helicoidal structure would be exceedingly diilcult and expensive to produce, and for this reason it would have very limited commercial success. Moreover, once the helicoidal structure has been produced and the contacts and wiring assembled thereon, the contacts are relatively inaccessible, `and the servicing or repair of thedevice presents a serious problem.

The main object' of the present invention is to devise an improved helicoidal switch structure which is easy to produce and which can be manufactured at low cost.

Another important object is to provide a helicoidal structure made up of a plurality of separately fabricated parts or units so assembled that any desired unit may be readily removed from the assembly for servicing or repair, without disturbing the other units.

A further object of the invention is to combine a helicoidal switch structure carrying a helical series of fixed contacts with a conventional rotary switch, and to simultaneously operate both by a common shaft.

A still further and more specific object is to devise a helicoidal switch structure made up of a plurality of relatively thin vilat panels which readily lend themselves to the use of printed circuits to provide the necessary series of iixed contacts.

With the above and other objects in View, and to improve generally on the details of such apparatus, the invention consists in the construction, arrangement and combination of parts hereinafter described and claimed, and illustrated in the accompanying drawings, formin part of this specification, and in which:

FIG. l is a side elevation `of one embodiment of our improved switch construction;

FIG. 2 is a vertical longitudinal section therethrough;

FIG. 3 is a fragmentary perspective view showing one of the panels and illustrating how it is skewed;

FIG. 4 is a transverse section through the helicoidal structure showing the fixed contacts carried by each panel;

' FIG. 5 is a similar view showing the reverse side of the panel illustrated in FIG. 4;

FIG. 6 is a fragmentary sectional view showing a slightly modified arrangement of movable contact;

FIG. 7 is a fragmentary perspective view showing how our improved selector switch can be adapted for use with normally closed circuits;

FIG. 8 is a side elevation of another embodiment of our invention;

FIG. 9 is a transverse section substantially on the line 9 9, looking in the direction of the arrows;

FIG. l0 is a vertical longitudinal section through the structure shown in FIG. 8;

FIG. 11 is a fragmentary perspective view showing one of the skewed segments making up the structure of FIGS. 8 and 10; and

FIG. l2 is a fragmentary perspective view illustrating how the contacts are assembled between two adjacent segments.

Referring to the drawings in detail and more particularly first to FIGS. l to 5, inclusive, our improved helicoidal structure is built up of a series of relatively thin dat panels assembled and spaced in a special way. While each panel might theoretically be formed of a single integral piece, it is preferred, for reasons hereinafter explained, to form each panel of two half sections. In the drawings, these half sections or segments are designated l and 2.

Each panel, which is shown as of square shape, has a circular opening in the center, 4the arcuate edges or inner surfaces 13 of this opening in each half section or segment extending through approximately To express it another way, each half panel or segment may be described as having a notch formed with an arcuate edge 13.

Each panel is divided diametrically into halves as indicated by the lines 3, 4 and each panel is provided with bolt holes 5 and 6, centered on the lines 3` and 4, as shown. Bolts 7 and 8, when the panels are assembled, extend through these holes, as hereinafter more fully explained.

The half panels or segments 1 and 2 also have other holes 9 and 10 extending therethrough, these holes being located near lthe c enter of each segment at a point spaced a substantial distance from the holes 5 and 6. When the panels are assembled, bolts 11 and 12 extend through these holes 9 and 10.

In order to hold the panels in the desired spaced relation, spacing sleeves 14 surround the bolts 11 and 12 and are interposed between the panels, and similar spacing sleeves 16 surround the bolts 7 and 8 and are interposed between the panels.

At each end of the assembled structure are end plates 17, through which all of the bolts extend.

Referring now more particularly to FIG. 3, it will be noted that we preferably secure each spacing sleeve 14 at one end to the adjacent segment as lby means of adhesive or cement 15j This isV to facilitate assembling and disassembling the segments, as hereinafter described. Referring again to FIG. 3, it will be particularly observed that each panel when assembled is skewed something'like an ordinary lock Washer, so that the end edges 18and'19 of the segments 1 and 2, which extend radially outward'from the inner arcuate edge, lie in different transverse planes. That is to say, they are laterally oifset. Furthermore, when the panels are assembled as shown in FIGS. l and 2, the end edges 18 and 19 of one panel abut similar end edges ofthe adjacent panels on each side so that the complete assembly forms a continuous helicoidal structure. Furthermore, it will be noted from an inspection of FIG. l that the dividing lines between all the abutting edges of the assembled panels lie in a common axial plane. Proper alignment is ensured by the iit of the bolts in the holes, prior to tightenmg.

lt will further be understood that the abutting edges of adjacent panels are clamped between the spacing 3 sleeves 16, when the bolts 7 and i5 are tightened. The abutting edges such as 3 and of adjacent panels are not secured or cemented together but are merely held in place by the clamping action of the spacing sleeves 16.

In FIGS. 1 and 2 we have shown, in addition to the helicoidal structure above described, a flat panel 20, the purpose of which will be hereinafter more fully described.

Referring now to FIGS. 4 and 5, it will be seen that on one surface of each half panel or segment 1 and 2 are printed circuits comprising a series of more or less radially extending conductors 2liJ the inner ends 22 of which are disposed around and adjacent the arcuate edge 13 and constitute fixed contacts, while the outer ends 23 constitute terminals to which the outside circuits may be connected.

On the reverse side of each half panel or segment, as shown in FIG. 5, is a pair of common contacts Z4 extending circumferentially around the arcuate edge 13 and united with conductors which may be suitably connected.

It will be understood that the arcuate edges 13 of the assembled panels dene a cylindrical space, and extending axially through this space in an operating shaft 27. A contact arm 26, carrying at one end a pair of opposed resilient movable contacts 2S and 29, is mounted on the shaft 27 to rotate therewith, but is capable of freely sliding longitudinally thereof. This is accomplished by forming in the arm 26 a slot 30 through which extends both the shaft 27 and a rod 31 spaced from the shaft 27 but rigidly connected therewith by means of arms 32, secured to the shaft as by set screws S3. The movable contacts 2S and 29 respectively engage the fixed contacts 22 of the printed circuits on one side of the helicoidal structure and the common contacts 24 on the opposite side of the helicoidal structure. The end of arm 26 adjacent the movable contacts is formed between such contacts with a groove to engage the arcuate edges of the panels to act as a guide, so as to take excessive strain off of the movable contacts.

The end 34 of the arm 26 opposite the contacts 28 and 29 is shaped to fit loosely between the inner edges of the panels, as clearly shown in FIG. 2, so that when the shaft 27 is turned such inner edges of the panels serve as guides to cause the arm 26 to travel axially along the helicoidal structure so that the movable contact 28 may selectively engage any one of the fixed contacts 22 throughout the length of the helicoidal structure.

In FIGS. l and 2 we have also illustrated, as abovementioned, a flat panel 2l) and the opposed sides of the inner edge of this panel are engaged by movable contacts 36 and 37 carried by arm 35 also mounted on shaft 27 and rod 31 by means of a slot 3S. Thus, when the shaft 27 is turned, both arms 26 and 35 are caused to rotate in synchronism, the arm 26 also travelling axially while the arm 35 remains in a fixed transverse plane. The arm 35 is held in such plane by means of a groove 39 formed therein at the end opposite the contacts 36 and 37, which groove freely engages the inner edge of the fiat panel 2d.

Any desired arrangement of fixed contacts can be mounted on the flat panel 2d. These contacts may, for example, be entirely independent of the contacts on the helicoidal structure and may thus operate like a conventional rotary switch.

On the other hand, we contemplate driving the shaft 27 by means of an electric motor and in this case contacts for controlling this motor can be mounted on the dat panel 20.

Alternatively, instead of mounting the common contacts on the surface of the helicoidal structure opposite the printed circuit contacts, we may mount a common contact on the flat panel 20. In this case, the arm 26 as shown in FIG. 6 would carry only a single contact 2S and this would be connected by a flexible conductor 40 with the contact 3e on the arm 35.

The foregoing description has been based on the assumption that the printed circuits to be selected are normally open and that engagement of the Contact 2S therewith serves to close them. rEhe same principle, involving the use of assembled panels constituting a helicoidal structure, can be employed in connection with an arrangement in which the circuits are normally closed and selectively opened. This is conventionally illustrated in FIG. 7 in which resilient contacts lil normally engage the inner ends of the printed circuits 21', these resilient contacts #il being connected by rivets or the like with the common contact on the opposite side of the panel 1. rIhe arm 26 is formed at its end with a lug 42 of insulating material which, when the arm rotates, engages under the resilient contacts 41 and lifts them off of the conductors 2l', thus selectively breaking the circuits.

The helicoidal structure made up of assembled segments as shown and described, has marked advantages so far as servicing and repairs are concerned. If for any reason it is desired to remove one of the segments or half panels, all that is necessary is to take out the bolt 11 or 12 passing through that particular half panel and loosen the bolts 7 and 8, thus releasing the clamping action of the spacing sleeves la, whereupon the half panel in question may be readily removed from the assembly, 'without disturbing any of the other panels.

To facilitate replacing this half panel or segment, we secure one end of the spacing sleeve 14 to it, as by means of cement I5, as already described and as best shown in FIG. 3. Thus when the half panel is removed, the spacing sleeve 14 comes away with it, and remains attached. When the half panel is replaced, this spacing sleeve may be readily inserted between the panel which carries it and the adjacent panel and lined up to receive the bolt.

While we have shown and described our improved method of forming a helicoidal structure by assembling skewed thin flat panels having printed circuits thereon, the same principle can be applied to producing a helicoidal structure in which radially disposed, separately formed contacts can be mounted in a helical path. This is shown in FIGS. 8 to l2, inclusive. The main difference between the two embodiments is that while in the first embodiment utilizing printed circuits, the convolutions of the helicoidal structure are spaced apart, in the second embodiment these convolutions lie close together and the contacts are held between them,

Referring now to FIGS. 8 through 12, we have shown an arrangement in which a helical series of contacts 43 is supported by means of a helicoidal structure made up of a plurality of arcuate segments 45 of insulating material. As best shown in FIG. 12, each of these segments has on one face a series of notches 44 in which the contacts 43 are received. The opposite face of each segment is flat as indicated at 47 and, when the segments are assembled, the fiat face of one abuts the portions 46 of the other lying between the notches 44 and thus confines the contacts 43 between the two segments.

As in the case of the first embodiment these segments are formed with bolt holes 48 and 49 midway of their length, and with other bolt holes 5t) and 51 centered on the division line between the half segments. Here again each segment is Shown as formed in two halves divided at the diametrically opposite points 52, but they can be made in one integral piece, like an ordinary lock washer, if desired. In any event, the segment is skewed and the two ends 53 are offset from each other and lie in different transverse planes. As in the first embodiment, when the segments are assembled the ends 53 of each segment abut the similar radially disposed ends of adjacent segments.

This embodiment employs the same contact arm 26 as above described, with a groove 26a at its end, engaging the inner ends of the fixed contacts, the movable contacts 28, 29 thereof engaging on each side of the inner ends of the helical series of fixed contacts 43, and the opposite end of the contact arm 34' being shaped to engage between such contacts, as shown in FIG. 10.

In this embodiment we employ a common contact 1n the nature of a flat annular band 54 held between two flat rings 4S', secured by the same bolts that hold the helicoidal segments in assemb-led relation. An arm 35 carries at one end contacts 36, 37 engaging the inner edge of this ring 54 and at the opposite end is formed with a groove 39 Ialso engaging the ring 54. A flexible conductor 55 connects the contacts 28, 29, with the contacts 36, 37 so as to complete the circuit to the common contact 54.

As before, when the shaft 27 is turned, the arm 26 not only rotates but travels axially along so as -to follow lthe helical path of the contacts 43.

From the `foregoing it will be seen that we have provided a helicoidal selector switch structure, the capacity of which is unlimited and which may be readily constructed and readily disassembled, and it is though that the many advantages of our invention will be obvious to those skilled in the art,

While we have shown and described the segments forming the helicoidal structure as extending through at least 180, we do not desire .to be limited to such an arrangement. In some cases, especially in the larger sizes, it may be desirable to use smaller segments extending extending through only 120 or even 90. This obviously may be accomplished by employing 4a larger number of bolts, some located at the meeting ends of the segments, and others passing -through the segments at points intermediate their ends.

Also while we have shown and described the segments as having radial ends, and while this is preferred, it is not essential. The meeting ends may lie in planes other than radial, extending outwardly from Ithe arcuate inner edges.

What is claimed is:

1. A selector switch comprising a supporting structure of insulating material shaped into helicoidal form, the inner edges of the structure defining a hollow cylindrical space, a continuous series of conductors supported on said helicoidal structure and extending out from the said inner edges thereof, and means, including a member mounted for rotation about the axis of said helicoidal structure for selectively controlling a circuit through any desired one of said conductors, said structure being made up of separately formed fiat panels each having an inner -arcuate edge, and having end edges extending outwardly therefrom, each of said panels being skewed so that the edges of its opposite ends lie in different transverse planes, and said panels being assembled in spaced relation with their said end edges abutting, the abutting end edges of all of said panels lying in a common axial plane, a bolt passing through all of said panels and disposed in such plane, and spacing sleeves surrounding said bolt between said panels to maintain them in proper spaced relation.

2. A selector switch comprising a supporting structure of insulating material shaped into helicoidal form, the inner edges of the structure defining a hollow cylindrical space, a continuous series of conductors supported on said helicoidal structure and extending out from the said inner edges thereof, and means, including a member mounted for rotation about the axis of said helicoidal structure for selectively controlling a circuit through any desired one of said conductors, said structure being made up of a series of separately formed flat panels each having its inner arcuate edge extending through at least 180 and having end edges extending outwardly therefrom, each of said panels being skewed so that the edges of its opposite ends lie in different transverse planes, and said panels being assembled in spaced relation with their said end edges abutting, the abutting end edges of all of said panels lying in a common longitudinal plane, a pair of bolts passing through all of said panels, the first of said bolts being disposed in such plane and the second displaced a substantial distance from such plane and from said abutting edges, spacing sleeves surrounding each bolt between said panels to maintain them in proper spaced relation, each sleeve around said second bolt being secured to one adjacent panel, but not the other, whereby when said second bolt is taken out, the sleeve and panel to which it is secured may be removed as a unit.

3. In a selector switch comprising a supporting structure of helicoidal form and a series of contacts supported on one of the helicoidal surfaces of said structure, said helicoidal structure being made up of a plurality of separately formed thin fiat panels of insulating material, each panel having a circular central opening and being divided diametrically into two similar halves, each half having a pair of radially extending end edges, each half being skewed so that its said end edges lie in different transverse planes, and said half panels being assembled in spaced relation in two sets with each end edge of each half panel in one set abutting the end edge of an adjacent half panel in the other set, the abutting end edges of all of said half panels lying in a common axial plane, a first pair of bolts passing through said series of abutting edges at diametrically opposite points, and a second pair of bolts, one passing through each set of said half panels at points intermediate their abutting end edges, and spacing sleeves surrounding each of said bolts between said half panels to maintain them in proper spaced relation, each half panel being clamped at its abutting edges between two adjacent sleeves, each sleeve surrounding each of said second pair of bolts being secured to one adjacent half panel but not to the other, whereby when one of said second pair of bolts is taken out and the first pair of bolts loosened, any desired half panel of that set may be removed without disturbing the others.

4. A selector switch comprising a supporting structure of helicoidal form, the inner edges of the structure defining a hollow, cylindrical space, said structure being made up of a plurality of arcuate segments of insulating material each extending through at least eac-h segment being skewed and said segments being assembled with their sides in substantial contact and with the ends of one segment abutting the ends of -adjacent segments so that their sides form continuous helicoidal surfaces, a helical series of circumferentially spaced, radially disposed fixed contacts supported between the said helicoidal surfaces and projecting inwardly into said cylindrical space, and a member mounted for rotation about and longitudinal travel along the axis of said structure, said member carrying a contact constructed to selectively engage any of said helical series of fixed contacts.

5. In a selector switch, the combination with a helicoidal insulating structure having inner arcuate edges defining a hollow cylindrical space, and having a series of fixed contacts carried by said helicoidal structure around such space, of a second separate insulating structure carrying one or more fixed contacts concentric with and disposed in a plane at right angles to the axis of the helicoid, means rigidly `binding together in co-axal assembled relation said helicoidal insulating structure and said second insulating structure a shaft extending axially through said space, a pair of arms independently mounted on said shaft, a contact carried by one arm disposed to sweep over and selectively engage the fixed contacts carried by said helicoidal structure, a contact carried by the other arm disposed to engage the fixed contact or contacts carried by said second insulating structure, a flexible conductor connecting the contacts carried by the two arms, and means for coupling said `arms to said shaft in such manner that they both turn therewith in unison, but one ar-m is free to slide on said shaft, said coupling means comprising a rod rigidly secured to said shaft parallel therewith but spaced radially therefrom, and both arms having openings through which said shaft and rod extend.

6. A selector switch according to claim l in which References Cfzed in the le of this patent UNITED STATES PATENTS 276,103 Webster Apr. 17, 1883 3 Gredell Dec. l0, Von Henke Apr. 14, Frank Apr. 5, Gay 51124, Reinschmdt lune 7, Black Ian. 28,

FOREIGN PATENTS France Apr. 30, Germany Tune 18, 

